In an exhaust heat recovery structure, a heat exchange portion (a tubular part) is configured such that a height of a lower inner surface is lowered from an inlet toward an outlet. Hence, when exhaust gas is condensed and condensed water is thereby generated inside the heat exchange portion (the tubular part), the condensed water flows from the inlet side toward the outlet side where the lower inner surface is lowered, and is then discharged to a piping part. Accordingly, the condensed water is unlikely to be collected inside the heat exchange portion.

There is provided a secondary air introduction device configured to introduce air into an exhaust port provided in a cylinder head of an engine by using a negative pressure in the exhaust port. A back-flow restriction member is provided between a reed valve and the exhaust port in an air introduction passage, and includes a plate part intersecting with an extension direction of the air introduction passage. The plate part has an air passing region in which the air flowing through the air introduction passage from an air intake unit toward the exhaust port is enabled to pass therethrough and a back-flow cutoff region in which exhaust air, which flows in a direction of directly colliding with at least a valve body of the reed valve, of exhaust air flowing back through the air introduction passage from the exhaust port is cut off.

A device (10) for introducing air into a combustion chamber of an internal combustion engine (11) through an exhaust manifold (14) of the engine includes a generally cylindrical valve body (12) supportable at an inner axial end in a hole formed through an engine exhaust manifold wall (13). A main fluid pathway (16) is formed within the valve body and extends between an intake (18) adjacent an outer axial end of the valve body and an exhaust opening (20) at the inner axial end of the valve body. A one-way check valve (22) is carried in the main fluid pathway and is configured to allow fluid flow along the main fluid pathway from the intake toward the exhaust opening and to block fluid flow along the main fluid pathway from the exhaust opening toward the intake.